The virtio-net driver can determine the required size of the config struct dynamically by inspecting the feature bits in host_features. The natural place to perform this calculation is within the driver's init routine. However, host_features isn't set until later when the device is plugged into a bus.
VirtioBusClass includes a callback method, device_plugged(), that allows the bus to perform additional setup tasks when a device is plugged into the bus. This patch set similarly extends VirtioDeviceClass to add a callback, bus_plugged(), to allow devices the same setup opportunity. This allows virtio-net to defer the config size calculation until host_features is available, which I think will be a better long-term fix to the problem addressed in e9016ee2bda1b7757072b856b2196f691aee3388. [PATCH 1/3] virtio: add bus_plugged() callback to VirtioDeviceClass [PATCH 2/3] virtio-net: implement bus_plugged() [PATCH 3/3] virtio-net: revert MAC address workaround hw/net/virtio-net.c | 20 +++++++++++++++++++- hw/virtio/virtio.c | 3 +++ include/hw/virtio/virtio.h | 1 + 3 files changed, 23 insertions(+), 1 deletion(-)
